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Adsorption of pesticides onto granular activated carbon in water treatment process
Kopecká, Ivana ; Hnaťuková, Petra (advisor) ; Pivokonský, Martin (referee)
The diploma thesis is aimed at adsorption processes during the removal of pesticides onto granular activated carbon (GAC) in the process of drinking water treatment. Adsorption onto GAC represents an efficient method for pesticides removal. High adsorption efficiency can be significantly reduced due to the occurrence of natural organic matter (NOM) in raw water, which involves AOM (Algal Organic Matter) produced by phytoplankton. Analogous to NOM, AOM probably affects adsorption of pesticides by two different mechanisms - a direct site competition and pore blockage effect, in dependence on the different molecular weight of particular AOM fractions. Equilibrium batch and kinetic adsorption experiments were performed using two types of GAC (Norit 1240 and Filtrasorb 400) and two pesticides (terbuthylazine and alachlor). In order to examine the effect of AOM on adsorption of pesticides, raw GAC and GAC preloaded by AOM were used. The effect of pH on the competitive adsorption of AOM was also evaluated. A solid phase extraction (SPE) method and gas chromatography with electron capture detection (GC-ECD) were used to determine pesticides in water samples. AOM was characterized using fractionation onto sorptive resins. The representation of apparent molecular weights of AOM proteins was determined by...
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Advanced removal methods of matter difficult to coagulate during drinking water treatment
Sichrová, Kateřina
Nowadays, drinking water treatment (DWT) is becoming more and more challenging due to the increasing anthropogenic pollution as well as due to the impacts of climate change. Water sources commonly comprise a cocktail of undesirable substances, the removal of which by the conventional DWT process based on coagulation/flocculation is often insufficient. This dissertation deals with advanced removal methods, particularly adsorption, usable for difficult to coagulate substances during DWT. Particular emphasis is placed on removing manganese, algal organic matter (AOM), and per- and polyfluorinated alkyl substances (PFAS). Additionally, in the case of emerging anthropogenic pollutants, attention was also paid to their occurrence and interactions in water. As part of the research, a new TiO2-based adsorbent was synthesized for Mn2+ removal. Since the prepared adsorbent showed high Mn2+ removal efficiency in a much wider range of pH values compared to the conventional demanganization method, which requires very high pH values, it could serve as a suitable alternative demanganization method. Regarding the removal of AOM, the influence of solution properties on its adsorption onto different types of granular activated carbon (GAC) was thoroughly investigated. It was found that the efficiency of AOM...
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Advanced removal methods of matter difficult to coagulate during drinking water treatment
Fialová, Kateřina ; Pivokonský, Martin (advisor) ; Mašín, Pavel (referee) ; Brányik, Tomáš (referee)
Nowadays, drinking water treatment (DWT) is becoming more and more challenging due to the increasing anthropogenic pollution as well as due to the impacts of climate change. Water sources commonly comprise a cocktail of undesirable substances, the removal of which by the conventional DWT process based on coagulation/flocculation is often insufficient. This dissertation deals with advanced removal methods, particularly adsorption, usable for difficult to coagulate substances during DWT. Particular emphasis is placed on removing manganese, algal organic matter (AOM), and per- and polyfluorinated alkyl substances (PFAS). Additionally, in the case of emerging anthropogenic pollutants, attention was also paid to their occurrence and interactions in water. As part of the research, a new TiO2-based adsorbent was synthesized for Mn2+ removal. Since the prepared adsorbent showed high Mn2+ removal efficiency in a much wider range of pH values compared to the conventional demanganization method, which requires very high pH values, it could serve as a suitable alternative demanganization method. Regarding the removal of AOM, the influence of solution properties on its adsorption onto different types of granular activated carbon (GAC) was thoroughly investigated. It was found that the efficiency of AOM...
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Influence of algal organic matter on coagulation of phytoplanktonic cells
Stránská, Štěpánka ; Pivokonský, Martin (advisor) ; Barešová, Magdalena (referee)
When algal or cyanobacterial populations increase in drinking water reservoirs, water treatment technologies have to cope not only with increased cell numbers but also with algal organic matter (AOM). The presence of cells and AOM in raw water causes some problems in the drinking water treatment process that can lead to the drinking water production of unsatisfactory quality. Residual algae cells and AOM can form toxic disinfection by-products (DBPs). Therefore, to maintain the cell integrity and prevent the release of AOM, it is essential for algae-polluted water treatment. This thesis examines the influence of AOM on coagulation of algal and cyanobacterial cells. The efficiency of coagulation is affected by various algae characteristics. The important have particularly the dependence of the coagulant dose on the cell surface area and the size and value of the surface charge of cells. It has been demonstrated that AOM can have not only negative but also positive influence on coagulation of cells. The presence of high concentrations particularly of low molecular weight (MW) AOM results in inhibition of coagulation. On the other hand, coagulation is improved by low concentration of high-MW AOM (particularly proteins) at approximately pH 4-6. Nowadays, for removal coagulated cells dissolved air...
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Characterisation and elimination of compounds difficult to remove during water treatment
Čermáková, Lenka
The Ph.D. thesis deals with the characterization of algal organic matter (AOM), which is difficult to remove in water treatment, and on the basis of AOM character, various methods for its elimination, e.g. coagulation, oxidation with subsequent coagulation and adsorption onto activated carbon are assesed. Special emphasis is placed on identifying the optimal conditions of the processes and on describing the mechanisms and interactions involved. In terms of anthropogenic micropollutants, the thesis deals with the highly topical issue of the occurrence of microplastics in water. It was found that the removal efficiency of the individual AOM components varies substantially depending on the elimination method used. The identified optimum conditions of individual methods and especially the mechanisms that apply to the removal of target substances varied widely. The non-proteinaceous fraction of AOM was removed with very low efficiency (max. 25%) by conventional coagulation even under optimized conditions (pH 6.6- 7.5 for aluminium sulfate as the coagulating agent and pH 7.5-9.0 for polyaluminium chloride) and it was given by the high content of low molecular weight (LMW) substances that are difficult to coagulate. The dominant coagulation mechanism was adsorption onto aluminium hydroxide precipitates....
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Characterisation and elimination of compounds difficult to remove during water treatment
Čermáková, Lenka ; Pivokonský, Martin (advisor) ; Sochorová, Helena (referee) ; Brányik, Tomáš (referee)
The Ph.D. thesis deals with the characterization of algal organic matter (AOM), which is difficult to remove in water treatment, and on the basis of AOM character, various methods for its elimination, e.g. coagulation, oxidation with subsequent coagulation and adsorption onto activated carbon are assesed. Special emphasis is placed on identifying the optimal conditions of the processes and on describing the mechanisms and interactions involved. In terms of anthropogenic micropollutants, the thesis deals with the highly topical issue of the occurrence of microplastics in water. It was found that the removal efficiency of the individual AOM components varies substantially depending on the elimination method used. The identified optimum conditions of individual methods and especially the mechanisms that apply to the removal of target substances varied widely. The non-proteinaceous fraction of AOM was removed with very low efficiency (max. 25%) by conventional coagulation even under optimized conditions (pH 6.6- 7.5 for aluminium sulfate as the coagulating agent and pH 7.5-9.0 for polyaluminium chloride) and it was given by the high content of low molecular weight (LMW) substances that are difficult to coagulate. The dominant coagulation mechanism was adsorption onto aluminium hydroxide precipitates....
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Adsorption of low molecular weight algal organic matter onto activated carbon during water treatment
Fialová, Kateřina ; Pivokonský, Martin (advisor) ; Kopecká, Ivana (referee)
This diploma thesis deals with the study of adsorption of low-molecular components of organic substances produced by phytoplankton - AOM (Algal Organic Matter) on AC (Activated Carbon) during drinking water treatment. For the experimental purpose in this thesis, there were used selected amino acids as low molecular substances of AOM that are difficult to remove by conventional water treatment process by coagulation. As adsorbent, there was used a detailed characterized of granulated activated carbon (GAC) - Filtrasorb TL 830 (FTL830) which is intended directly for the purpose of water treatment. There were realizing the equilibrium batch adsorption experiments with three different model amino acids - arginine (Arg), phenylalanine (Phe) and aspartic acid (Asp). There was investigated the efficiency of removing amino acid depending on the solution temperature and pH. Results of the adsorption experiments have shown that the temperature affects the adsorption efficiency. Adsorption is essentially described as an exothermic process but the adsorption of Arg and Phe from an aqueous solution to GAC occurs more efficiently at higher temperatures. It means that the adsorption is the endothermic process. In the case of Arg adsorption, the temperature was found to influence adsorption efficiency less than...
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Influence of preoxidation by potassium permanganate on coagulation of nonproteinaceous compounds produced by alga Chlorella vulgaris
Přech, Jiří ; Pivokonský, Martin (advisor) ; Novotná, Kateřina (referee)
6 Abstract: The presence of phytoplankton and its products (AOM) in source water is a current challenge in water treatment processes. The production of AOM increases with anthropogenic eutrophication of ecosystems. AOM impair the water treatment processes and may form harmful disinfection by-products. The traditional water treatment process is a coagulation, which is very efficient in removing phytoplankton cells, but this is not the case when removing some kinds of AOM. Especially its nonproteinaceous fraction with low molecular weight, which can represent majority of total organic carbon, is removed with very low efficiency. The removal of AOM by coagulation can be enhanced by preoxidation. This thesis examines the influence of preoxidation by potassium permanganate of nonproteinaceous fraction of COM of algae Chlorella vulgaris on its coagulation by aluminium sulphate and polyaluminiumchloride. To compare, solutions with nonproteinaceous COM were coagulated with and without preoxidation by five different doses of permanganate (0,025; 0,05; 0,1; 0,15 a 0,2 mg KMnO4 mg-1 DOC). The doses of permanganate and time need for oxidation (30 minutes) were determined by decreased DOC and permanganate during preoxidation experiments. The maximal DOC removals achieved both with and without preoxidation were 17 %...
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Influence of algal organic matter on coagulation of phytoplanktonic cells
Stránská, Štěpánka ; Pivokonský, Martin (advisor) ; Barešová, Magdalena (referee)
When algal or cyanobacterial populations increase in drinking water reservoirs, water treatment technologies have to cope not only with increased cell numbers but also with algal organic matter (AOM). The presence of cells and AOM in raw water causes some problems in the drinking water treatment process that can lead to the drinking water production of unsatisfactory quality. Residual algae cells and AOM can form toxic disinfection by-products (DBPs). Therefore, to maintain the cell integrity and prevent the release of AOM, it is essential for algae-polluted water treatment. This thesis examines the influence of AOM on coagulation of algal and cyanobacterial cells. The efficiency of coagulation is affected by various algae characteristics. The important have particularly the dependence of the coagulant dose on the cell surface area and the size and value of the surface charge of cells. It has been demonstrated that AOM can have not only negative but also positive influence on coagulation of cells. The presence of high concentrations particularly of low molecular weight (MW) AOM results in inhibition of coagulation. On the other hand, coagulation is improved by low concentration of high-MW AOM (particularly proteins) at approximately pH 4-6. Nowadays, for removal coagulated cells dissolved air...
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ADSORPTION OF ALGAL ORGANIC MATTER PRODUCED BY MICROCYSTIS AERUGINOSA ONTO ACTIVATED CARBON
Krsová, Magdalena ; Pivokonský, Martin (advisor) ; Benešová, Libuše (referee)
The aim of this diploma thesis is to evaluate the efficiency of two types of granular activated carbon (GAC), Filtrasorb TL 830 and Picabiol 12x40, for the adsorption of cellular peptides with low molecular weight produced by cyanobacterium Microcystis aeruginosa that are hardly removable during the coagulation/flocculation processes. The effect of different carbon properties (surface charge, textural characteristics), peptide properties (molecular size, surface functionality and charge) and solution characteristics (ionic strength and pH value) on the peptide uptake was investigated using laboratory equilibrium and kinetic adsorption experiments. The results showed that adsorption of peptides was influenced by the charge conditions in adsorption system that depend on solution pH. The pH value influences surface charge and the point of zero charge (pHpzc) of GAC as well as dissociation and protonization of peptide functional groups. It was found that efficiency of the peptide adsorption increased with decreasing pH value for both GACs. Under these conditions adsorption was enhanced by attractive electrostatic interactions between GAC surface and peptide functional groups and was also positively influenced by the conformation changes in peptide structure. GAC Picabiol 12x40 showed the total highest...
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